Malaria is an infectious disease caused by protozoan parasites in the genus Plasmodium that are transmitted from host to host by mosquitoes. Malaria initially manifests with mild to severe symptoms including: chills, fever, fatigue, headache, and nausea. Later symptoms include severe anemia, and blood clotting, which can lead to brain damage and other complications, and death. Although five species of Plasmodium (P. falciparum, P. vivax, P. ovale, P. malariae, and P. knowlesi) can infect humans, the majority of malarial deaths are caused by P. falciparum and P. vivax. 
Nearly half of the world's population is at risk for malaria. The World Health Organization (WHO) estimates that about 200 million cases and about 600,000 deaths occur each year (WHO, World Malaria Report, 2014). Increasing drug resistance has intensified the need for new therapeutics. The development of drugs that can target more than one parasite stage has been identified as an important strategy for controlling malaria. Particularly desirable are treatments with transmission-blocking properties.